- #1
justagirl
- 29
- 0
Suppose a 50kg block slides along a
horizontal surface where the coefficient of kinetic friction
between the block and the surface is uk = 0.60. A force F =
400 N is now applied, where the
angle of the force above horizontal is 20°.
What is the magnitude of the acceleration of the block?
0.54 m/s2
2.31 m/s2
3.27 m/s2
6.78 m/s2
8.11 m/s2
Here's what i did:
F(x-net) = F(applied) - F(friction) = ma
a = F(applied) - F(friction) / m
= (400)(cos 20) - (50 * 9.8 * 0.6) / 50
= 375 N - 294 N / 50 kg
= 1.67 m/s2
I checked my numbers quite a few times and keep getting
1.67, which is not one of the answer choices. The only thing
I saw was that 3.72 m/s2 is exactly double what I got, but I
can't find an explanation for that.
Thanks!
horizontal surface where the coefficient of kinetic friction
between the block and the surface is uk = 0.60. A force F =
400 N is now applied, where the
angle of the force above horizontal is 20°.
What is the magnitude of the acceleration of the block?
0.54 m/s2
2.31 m/s2
3.27 m/s2
6.78 m/s2
8.11 m/s2
Here's what i did:
F(x-net) = F(applied) - F(friction) = ma
a = F(applied) - F(friction) / m
= (400)(cos 20) - (50 * 9.8 * 0.6) / 50
= 375 N - 294 N / 50 kg
= 1.67 m/s2
I checked my numbers quite a few times and keep getting
1.67, which is not one of the answer choices. The only thing
I saw was that 3.72 m/s2 is exactly double what I got, but I
can't find an explanation for that.
Thanks!