A rock is dropped from 20 feet above the surface of the Earth. Which of the following is true? a. It falls because of the combined effects of gravity and air pushing downward upone it. b. It falls because of a natural tendency for rocks to rest upon the Earth c. It speeds up as it falls because of a nearly constant force of gravity acting on it. d. It speeds up as it falls because of an increasing force of gravity acting upon it. e. It quickly reaches a maximum speed, then falls at a constant rate.

Q: 5. An airplane with a weight of 11,000 N cruises at 180 km/h in level flight 2300 m above the…

A: Given: Weight of plane =11000 N Speed v =180 kmph

Q: 3. There is a common misconception that astronauts in orbit seem to float because "there is no…

A:

Q: Which has more mass, a kilogram of feathers or a kilogram of iron? a. Feathers C. Both b. Iron d.…

A: To identify :  Which has more mass : 1 kg of feathers or 1 kg of iron

Q: Which graph below represents the relationship between velocity and time for an object thrown…

A: we know that  v = u +at where v is final velocity u is initial veloctiy a is acceleration  t is time…

Q: . There are about 160,000 road accidents in Canada every year. According to the Transportation…

A: (a) During collision of two vehicles  vehicle gets stopped instantly but our bodies remain in motion…

Q: Calculate the time needed for a 0.600 kg hammer to reach the surface of the Earth if dropped from…

A:

Q: An astronaut on the Moon simultaneously drops a feather and a hammer. The fact that they land…

A: Introduction: According to Newton's law of gravity, two massive bodies exert a force of attraction…

Q: An 8.0 kg object moving with an initial velocity of 8.0 m/s on a surface comes to rest due to…

A: m = 8 kg  Initial velocity (v) = 8.0 m/s  Horizontal distance (x) = 10 m  g =10 m/s2

Q: Compare the velocity of water coming out of the bottom of a water tower of height h (vt) and the…

A: Given: velocity of water from bottom of tank =vt velocity from a height=vf

Q: Skydiving If a body of mass m falling from rest under the action of gravity encounters an air…

A:

Q: A trampolinist flies straight up into the air, then back down onto the trampoline, where she comes…

A: Let us say, mass of the trampolinist = m Acceleration of the trampolinist is a If we take upward…

Q: When a feather and a coin are dropped from the same height at the same time in vacuum Select one: a.…

A: Air Resistance: Air resistance can be defined as the opposing or frictional force, which tends to…

Q: 3. The organizers of a snowboarding competition have decided that they need to get an engineer to…

A:

Q: When considering relative velocity, which of the following scenarios would result in a runner being…

A: A tail wind is a wind that flows in the direction of travel of object . A head wind is the wind that…

Q: The height of a ball is thrown straight up sith a certain force is a function of the time (t) from…

A: height of the ball thrown straigh up is given by the function : f(t) = -0.5gt2 + 40 t

Q: 25. Two objects of unequal mass are dropped from the same height near the surface of the earth.…

A:

Q: 2. Skydiving If a body of mass m falling from rest under the action of gravity encounters an air…

A:

Q: A boxer punches a punching bag. The time of impact of the glove and the bag is 0.01 s and the mass…

A: Average force acting on the glove is given by change in momentum per time. So  F=(m1v1-m2v2)/t…

Q: A hot air balloon is descending at 10[m/s]. To slow the rate of descent the pilot drops a weight…

A:

Q: If an elevator is descending toward the ground floor of a building and slowing down, then its: Group…

A: Given that , elevator is descending toward the ground floor of a building and slowing down . It…

Newton's First Law of Motion

If a very smooth ball is rolled down an inclined surface with zero friction, the ball will continue to roll indefinitely for an infinite time, in an attempt to reach to the same height on the opposite hill!