A motorist makes a trip of 180 km. For the first 90 km she drives at a constant speed of 30kph. At what constant speed must she drive the remaining distance if her average speed for the entire trip is to be 40 kph? (A) 50 kph (B) 60 kph (C) 70 kph (D) 80 kph

A motorist makes a trip of 180 km. For the first 90 km she drives at a constant speed of 30kph. At what constant speed must she drive the remaining distance if her average speed for the entire trip is to be 40 kph? (A) 50 kph (B) 60 kph (C) 70 kph (D) 80 kph

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Related questions

Q: You walk 5 meters from point A to point B in 3 seconds. You then come back to point A in another 2…

A: Given, Distance = 5m Time taken to reach point A to B = 3 sec Time taken to reach point A back = 2…

Q: A rock, released at rest from the top of a tower, hits the ground after 1.5 s. What is the speed of…

A: When the rock is released from the top of the tower, its potential energy is converted to kinetic…

Q: From a speed of 60 kph, a train decelerates at the rate of 2 m/min² along the path. How far in…

Q: Tectonic plates are large segments of the Earth's crust that move slowly. Suppose that one such…

Q: An object moves along the positive x-axis with a speed of V, =4 m/s for 2 seconds, then moves along…

A: Given: The velocity V1 is 4 m/s. The time duration is 2 s. The velocity V2 is 7 m/s. The time…

Q: The operating speed of a personal computer is 200 gigahertz. This is one-third the speed of a newer…

A: Operating speed of personal computer = 200 gigahertzSpeed of newer model is 3 times of operating…

Q: A car accelerates with a constant acceleration of 1.5 m s2 along a long straight road. How long does…

Q: A bobsled zips down a frictionless ice track starting at 150 m vertical distance up the hill. What…

A: Given information:Initial velocity of the sled (u) = 0Total height of the mountain (H) = 150 mThe…

Q: In the late 1800's, twenty-five percent of the world's nickel production came from Nickel Mines,…

A: Write the kinematic equation for acceleration

Q: Your grandfather had to walk to school uphill, both ways, but one way he went at 5.0 km/hr, and the…

A: Given: Speed of the walking to school from home v1 = 5.0 km/hr Speed of the walking to home from…

Q: Suppose a person drops 20.0 m (about 5 floors) from a burning building and onto an air bag. (a) What…

A: In this question we have to determine the maximum speed when a person falls from a height of 20 m.…

Q: Three people are walking. The first person walks at a slow pace, the next walks at a medium pace,…

Q: In a 5000 m race, the athletes run 1212 laps; each lap is 400 m. Kara runs the race at a constant…

A: The total distance of the race, D=5000mEach lap distance = 400 mKara runs the race at a constant…

Q: Daryl and Cynthia leave home at 7 am, heading in opposite directions for work. Cynthia usually…

A: Given, Both daryl and cynthia leave at same time. Cynthia takes 20 min to biking whereas Daryl takes…

Q: A rock is thrown from a bridge 21.5 m above water with an initial speed of 14 m/s. Assuming…

A: Given data: The height above water is h=21.5 m. Initial speed is u=14 m/s.

Q: ou are driving a car along a straight road at 133 kph. Suddenly, you saw a cat crossing the road…

Q: While dusting a bookshelf at the local college's huge library, Jean accidentally knocks a book off…

A: From equation of motion, final velocity of the body is v2 = u2 + 2as Where, v = final velocity u =…

Q: While dusting a bookshelf at the local college's huge library, Jean accidentally knocks a book off…

A: Given Height from book dropped = h = 3.48 m Initial velocity = u = 0 m/s We have to calculate the…

Q: A rock is thrown from a bridge 19.5 m above water with an initial speed of 17 m/s. Assuming…

A: According to the law of conservation of energy,

Q: A ball is thrown downward from the top of a 40.0 m tower with an initial speed of 12.0 m/s. Assuming…

A: Height of building= 40 m Initial speed= 12 m/s Ball is thrown downward.

Q: While dusting a bookshelf at the local college's huge library, Jean accidentally knocks a book off…

A: Initial speed of the book, u = 0 m/s Height of the shelf, h = 3.83 m Acceleration due to gravity, g…

Q: Your car gets 34.7 mi/gal on a trip. How many km/L did it get? (3.79 L = 1 gal; 1 mi = 1.61 km) L…

Q: At t=0, a particle starts with an initial velocity of 10 i m/s and accelerates uniformly at (-2.0 i…

A: Given initial speed (u)=10 m/s Acceleration (a)=(-2.0 i +4.0 j) m/s2 Required speed at t=5 s

Q: A boy tosses a coin straight up to 2.2 m. Suppose the height when the coin leaves his hand is 1.3 m.…

A: Initial height of the coin in boy's hand = 1.3 m The height of the coin when it tosses = 2.2 m The…

Q: A rock is thrown from a bridge 18 m above water with an initial speed of 15.5 m/s. Assuming…

A: The objective of the question is to find the final speed of the rock when it hits the water. We will…

Q: A space probe on the surface of Mars sends a radio signal back to the Earth, a distance of 7.27 ✕…

A: The time taken by the wave is given by:

Q: ski jumper starts from rest 54.1 m above the ground on a frictionless track and flies off the track…

Q: Julie drives 91 mi to Grandmother's house. On the way to Grandmother's house, Julie drives half the…

A: Average speed is, vavg=total distancetotal time Total distance traveled by Julie on the way to…

Q: A ball is dropped (from rest) from a window and hits the ground with a speed of 7.0m/s. If the ball…

Q: A space probe on the surface of Mars sends a radio signal back to the earth, a distance of 7.37 x…

Q: External stimuli are communicated to the brain by means of electrical signals propagating along with…

A: As we know,speed is the ratio of distance travelled by time taken.

Q: A student drops an object out the window of the top floor of a high-rise dormitory. (a) Neglecting…

Q: rage speed is equal to:

A: A person running First distance d1 = 3.5 km Time t1 =30 min = 0.5 hr Second distance d2 = 2.5 km…

Q: A ball is thrown straight up with a speed of 30 m/s, and air resistance is negligible. (a) How long…

A: Given: Initial speed of ball u = 30 m/s.

Q: While dusting a bookshelf at the local college's huge library, Jean accidentally knocks a book off…

Concept explainers

Distance and Speed

The speed, distance and time relation forms the basis of study of motion. You will need these concepts in the study of Mechanics. This concept is applicable for students who are studying the following courses –

Question

4.
A motorist makes a trip of 180 km. For the first 90 km she drives
at a constant speed of 30kph. At what constant speed must she
drive the remaining distance if her average speed for the entire
trip is to be 40 kph?
(A) 50 kph
(B) 60 kph
(C) 70 kph
(D) 80 kph

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 2 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.

Similar questions

A rock is thrown from a bridge 21 m above water with an initial speed of 14 m/s. Assuming negligible air resistance, what is the speed that the rock hits the water with, in meters per second?
The van travels over the hill described by y=(-1.5x10 ')x²+15) ft. If it has a constant speed of 71 ft/s, determine the x component of the van's velocity when x = 50 ft. y= (-1,5(10- + 15) ft 15 ft 100 t
Fast Car: On a hot day in the flats, the temperature is 103.6 degrees. A driver finds an empty, flat stretch of desert that is 1776 meters long and decides to push the limits of his car. He finds the car can accelerate from 0 to 60 mph (26.8 m/s) in 4.30 s. Now he wants to see how fast the car can go. Assume the car maintains the same average acceleration until it reaches its top speed of 84.8 m/s. (a) How long will it take the car to reach its top speed? (b) How far will the car travel before it reaches its top speed?
A ball is thrown straight up in the air with an initial speed of 10 m/s. Ignore air resistance and take g = 10m/s2. What is the speed of the ball when it reach 5 m above the ground? O m/s 5 m/s 5/2 m/s 10 m/s 10/2 m/s
You are throwing an egg straight down from the roof of a building at a speed of 13.6 m/s. The building has a height of 37.9 m. Ignoring air resistance, at what speed does the egg hits the ground?
Evan is just leaving his house to visit his grandma. Normally, the trip takes him 25 minutes on the freeway, going 55 mph. But tonight he’s running 5 minutes late. How fast will he need to drive on the freeway to make up the 5 minutes?Express your answer in miles per hour.
A parachutist after bailing out falls 50 m without friction. When the parachute opens, it decelerates at 2 m/s2. He reaches the ground with a speed of 3 m/s. At what height, did he bailout? (a) 293 m (b) 111 m (c) 91 m (d) 182 m
As you drive your car along a country road at night, a deer jumps out of the woods and stands in the middle of the road ahead of you. This occurs just as you are passing from a 55-mi/h zone to a 50-mi/h zone. At the 50-mi/h speed-limit sign, you slam on the car’s brakes, causing them to lock up, and skid to a stop inches from the startled deer. As you breathe a sigh of relief, you hear the sound of a police siren. The policeman proceeds to write you a ticket for driving 56 mi/h in 50-mi/h zone. Because of your preparation in physics, you are able to use the 25-m-long skid marks that your car left behind as evidence that you were not speeding. What evidence do you present? You must use work/energy methods to solve this problem!The coefficientsof friction between car tires and dry concrete are (s=1.0, k=0.80).
A hippopotamus can run up to 9.86 m/s. Suppose a hippopotamus uniformly accelerates 0.28 m/s² until it reaches a top speed of 9.86 m/s. If the hippopotamus has run 25.1 m, what is its initial speed in m/s? (round your answer to two decimal places; DO NOT include units)
A ball is thrown straight up in the air with an initial speed of 40 m/s. Ignore air resistance and take g- 10m/s2. What is the speed of the ball when it reach 40 m above the ground? 20 m/s 20/2 mis 2/20 mis 3/20 m/s 20/3 m m/s
A runner covers a distance of 15.0 m in 6 s to move from x O to x = 4.0 m. What is the average speed of the runner? 1.17 m/s 4.00 m/s 2.50 m/s 0.667 m/s
Gretchen runs the first 4.0 km of a race at 6.0 m/s. Then a stiff wind comes up, so she runs the last 1.0 km at only 5.0 m/s .