M*g = 13*9.8 = 127.4 N. = Wt. of box.
Fp = 127.4*sin55 = 104.4 N. = Force parallel with ramp.
Fki = u*Fn = 0.3*127.4*Cos55 = 21.9 N. = Force of kinetic friction.
Fe = 160 N. = Force exerted.
A. Fp-Fki+Fe = M*a.
104.4-21.9+160 = 13*a,
13a = 242.5,
a = 18.7 m/s^2.
B. Fe-Fki-Fp = M*a.
160-21.9-104.4 = 13a,
13a = 33.7,
a = 2.6 m/s^2.
A box with mass 13.0 kg moves on a ramp that is inclined at an angle of 55.0∘ above the horizontal. The coefficient of kinetic friction between the box and the ramp surface is μk = 0.300.
FIND
A) Calculate the magnitude of the acceleration of the box if you push on the box with a constant force 160.0 N that is parallel to the ramp surface and directed down the ramp, moving the box down the ramp.
B) Calculate the magnitude of the acceleration of the box if you push on the box with a constant force 160.0 N that is parallel to the ramp surface and directed up the ramp, moving the box up the ramp.
1 answer