Questions from Modern Physics

Q: A 70-kg astronaut floating in space in a 110-

A 70-kg astronaut floating in space in a 110-kg MMU (manned maneuvering unit) experiences an acceleration of 0.029 m/s2 when he fires one of the MMU’s thrusters. (a) If the speed of the escaping N2 ga...

Q: A small rocket burns 0.0500 kg of fuel per second

A small rocket burns 0.0500 kg of fuel per second, ejecting it as a gas with a velocity relative to the rocket of magnitude 1600 m/s. (a) What is the thrust of the rocket? (b) Would the rocket operate...

Q: The maximum energy that a bone can absorb without breaking depends on

The maximum energy that a bone can absorb without breaking depends on characteristics such as its cross-sectional area and elasticity. For healthy human leg bones of approximately 6.0 cm2 cross-sectio...

Q: Obviously, we can make rockets to go very fast, but

Obviously, we can make rockets to go very fast, but what is a reasonable top speed? Assume that a rocket is fired from rest at a space station in deep space, where gravity is negligible. (a) If the ro...

Q: (a) What is the magnitude of the momentum of a

(a) What is the magnitude of the momentum of a 10,000-kg truck whose speed is 12.0 m/s? (b) What speed would a 2000-kg SUV have to attain in order to have (i) the same momentum? (ii) the same kinetic...

Q: A bat strikes a 0.145-kg baseball. Just

A bat strikes a 0.145-kg baseball. Just before impact, the ball is traveling horizontally to the right at 40.0 m/s; when it leaves the bat, the ball is traveling to the left at an angle of 30° above h...

Q: At time t = 0 a 2150-kg rocket in outer

At time t = 0 a 2150-kg rocket in outer space fires an engine that exerts an increasing force on it in the +x-direction. This force obeys the equation Fx = At2, where t is time, and has a magnitude of...

Q: Experimental tests have shown that bone will rupture if it is subjected

Experimental tests have shown that bone will rupture if it is subjected to a force density of 1.03 × 108 N/m2. Suppose a 70.0-kg person carelessly roller skates into an overhead metal beam that hits h...

Q: A 2.00-kg stone is sliding to the right

A 2.00-kg stone is sliding to the right on a frictionless, horizontal surface at 5.00 m/s when it is suddenly struck by an object that exerts a large horizontal force on it for a short period of time....

Q: To warm up for a match, a tennis player hits the

To warm up for a match, a tennis player hits the 57.0-g ball vertically with her racket. If the ball is stationary just before it is hit and goes 5.50 m high, what impulse did she impart to it?