physics - forces
A person pushes a 16.0 kg lawn mower at constant speed with a force of 70.0 N directed along the handle, which is at an angle of è = 45.0° to the horizontal. Calculate the force the person must exert on the lawn mower to accelerate it from rest to 1.2 m/s in 2.0 seconds (assuming the same ing force which is 70cos45).
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The force the person must exert on the lawn mower to accelerate it from rest to 1.2 m/s in 2.0 seconds is 197.1 N. This is calculated by using the equation Force = mass x acceleration, where acceleration = Δv / t. Here, Δv = 1.2 m/s and t = 2.0 s, so Force = 16.0 kg x (1.2 m/s / 2.0 s) = 16.0 kg x 0.6 m/s2 = 9.6 kg m/s2. Since the force the person exerts on the lawn mower is 70cos45, the net force is 9.6 kg m/s2 + 70cos45 = 197.1 N. This is the force required to accelerate the lawn mower from rest to 1.2 m/s in 2.0 seconds.
