. . A carpenter swings a 3-kg hammer so that its speed is 5 m/s just before it s

Question

.

. A carpenter swings a 3-kg hammer so that its speed is 5 m/s just before it strikes a nail. The nail isdriven 6 mm into a block of wood.a. Assuming that a constant force resisted the motion of the nail, what must have been the

magnitude of the force?

Known:

Unknown:

Strategy:

Solution:

b. Compare the force to the weight of the hammer.

2. Sally Ride was the first American woman in space. If she had a mass of about 55-kg, what would abathroom scale read if Ride stood on it while in a rocket taking off vertically with an acceleration of3g?

Known:

Unknown:

Strategy:
Solution:

                                                          

Explanation / Answer

(1)When the hammer strikes the nail at that moment
energy with hammer is = (1/2)mV2
where m is mass and V is velocity
therefore energy = 0.5*3*52 = 37.5 J
after nail travel 6 mm then the energy will be zero.
Therefore According to work energy theorem
Change in kinetic energy = work done = Force*distance
Therefore
Force = Change in kinetic energy/ distance = 37.5 /6 = 6250 N
(b) Weight of the hammer = 3*9.81 = 29.43 N
(2) mass of Sally (M) = 55 kg
When rocket will move with an acceleration 3g then the reading of the scale would be
= Mg + M(3g) = 4Mg = 220g = 2158.2 N

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.