Mechanics | Relativity Answers

Starting from rest,a sprinter reaches his top velocity in 3 seconds.He runs a distance of 24m in the 3 secinds.What is his acceleration?

A satellite moves in an elliptical orbit with the Earth at one focus. At the perigee its
speed is v and its distance from the centre of the Earth is R . If the eccentricity of its
orbit is 0.5, calculate its speed at the apogee.

A large container of water is placed on a set of scales which initially read 0.485 kg. A ball is hung in the air from another set of scales which initially read 0.112 kg.

The ball is lowered into the large container until it is fully submerged.

The readings on both scales are now 0.496 kg and 0.101 kg respectively.

What is the density of the ball? (to 3 s.f and in kg m−3)

(ρwater = 1000 kg m−3)

A bicycle rider travels 250m north and 160 m northwest. What is the riders displacement? What distance does the rider cover?

A particle moves along the curve y=1/3x^3+2 where x and y are in meters.When x=.8, the x component of the velocity is 10m/s what is the total velocity

The wing of an airplane has an average cross-sectional area of 13 m2 and experiences a lift force of 78,000 N. What is the average difference in the air pressure between the top and bottom of the wing?

A scale reads 274 N when a piece of brass is hanging from it. What does it read (in N) when it is lowered so that the brass is submerged in water?

An ebony log with volume 17.2 ft3 is submerged in water. What is the buoyant force on it (in lb)? (Enter the magnitude.)

Two 1.10-kg carts on a low-friction track are rigged with magnets so that the carts repel each other when they approach each other. One cart has an initial velocity of +0.323 m/s, and the other has an initial velocity of -0.147 m/s.
What is the maximum energy stored in the magnetic field during the collision, assuming that the carts never touch each other?

an airplane has a speed of 120km/h in still air. the plane is headed 30 degrees east of north when a wind starts blowing due east at 30km/hr. What is the planes speed relative to the ground?