A man pulls a sled at a constant velocity across a horizonta

A man pulls a sled at a constant velocity across a horizontal snow surface. If a fore of 80 N is being applied to the sled rope at an angle of 53 degree to the ground, what is the force of friction between sled and snow? A) 40 N B) 20 N C) 64 N D) 48 N E) 80 N A block of mass 5.0 kg rests on a horizontal surface where the coefficient of sliding kinetic friction between the two is 0.2. A string attached to the block is pulled horizontally, resulting in a 2 m/s^2 acceleration by the block. Find the tension in the string. (g - 9.8 m/s^2) A) 9.8 N B) 5 N C) 10 N D) 0.2 N E) 19.8 N If Force - (-4, 1) and Displacement = (-2, -3), find the angle in degrees between the two vectors. A) 88 B) -52 C) 125 D) 45 E) 71 If Force - 3 x^3 - 2 x, find the work done by the force for a distance of x = 1 to x = 3. A) 0 B) 52 C) 81 D) 20 E) 60.75 A spring of spring constant of 10000 N/m and compressed by, 3 m accelerates a 5 kg mass down a frictionless incline from a height of 4 m. What is the speed of the mass at the bottom of the inclined plane? A) 24 m/s B) 16 m/s C) 8.85 m/s D) 12 m/s E) 3 m/s

Solution

1) F_net = F_applied - F_friction

a = 0, F_net = 0

F_f = 80 * cos 53

= 48.1 N

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2) w = m g = 0.5 * 9.8 = 49 N

Horizontal acceleration T - f_k = m a

T = (5 * 2) + (0.2 * 49)

= 19.8 N