- #1

JohnTheGreat101

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- 0

- Homework Statement
- Suppose a 15.0 g dart is fired into a wooden block that is mounted on wheels with a total

mass of 10.0 kg. The time required for the block to travel a distance of 45.0 cm is

measured after the dart lodges into the block. This can easily be accomplished with a

pair of photocells and an electric clock. If the coefficient of friction between the

wheels and floor is 0.1435 and the measured time to come to a stop is .80 seconds, what

is the muzzle velocity of the dart? (assume no drag force on the dart before it hits the

block).

- Relevant Equations
- x= vt + 1/2 at^2

m1v1=m2v2

This is a practice problem so I know that the answer is 750 m/.s. Not totally sure what to do with the friction or if any of my listed equations are relevant here but here goes what I've tried:

.45 kg = v(0.8 sec) + 1/2(-9.8 *0.1435) * (0.8)^2

.45 kg = v(0.8) + 1/2(-1.4063) * 0.64

.45=v(0.8) - 0.450015

0.900016= V(0.8)

V does not equal 1.12 m/s

.45 kg = v(0.8 sec) + 1/2(-9.8 *0.1435) * (0.8)^2

.45 kg = v(0.8) + 1/2(-1.4063) * 0.64

.45=v(0.8) - 0.450015

0.900016= V(0.8)

V does not equal 1.12 m/s