# Physics equations/04-Dynamics: Force and Newton's Laws/Q:sled

## A

1 A sled of mass 5.4 kg is at rest on a rough surface. A string pulls with a tension of 43.4N at an angle of 31 degrees above the horizontal. What is the magnitude of the friction?

 a) 24.46 N. b) 28.13 N. c) 32.35 N. d) 37.2 N. e) 42.78 N.

2 A sled of mass 5.3 kg is at rest on a rough surface. A string pulls with a tension of 44.9N at an angle of 57 degrees above the horizontal. What is the normal force?

 a) 8.17 N. b) 9.39 N. c) 10.8 N. d) 12.42 N. e) 14.28 N.

3 A sled of mass 5.9 kg is at rest on a perfectly smooth surface. A string pulls with a tension of 47.3N at an angle of 48 degrees above the horizontal. How long will it take to reach a speed of 10.8 m/s?

 a) 1.15 s b) 1.32 s c) 1.52 s d) 1.75 s e) 2.01 s

4 A sled of mass 2.1 kg is on perfectly smooth surface. A string pulls with a tension of 17.5N. At what angle above the horizontal must the string pull in order to achieve an accelerations of 2.8 m/s2?

 a) 70.4 degrees b) 80.9 degrees c) 93.1 degrees d) 107 degrees e) 123.1 degrees

## B

1 A sled of mass 5.7 kg is at rest on a rough surface. A string pulls with a tension of 41.6N at an angle of 34 degress above the horizontal. What is the magnitude of the friction?

 a) 19.72 N. b) 22.68 N. c) 26.08 N. d) 29.99 N. e) 34.49 N.

2 A sled of mass 5.4 kg is at rest on a rough surface. A string pulls with a tension of 40.4N at an angle of 39 degress above the horizontal. What is the normal force?

 a) 27.5 N. b) 31.62 N. c) 36.36 N. d) 41.82 N. e) 48.09 N.

3 A sled of mass 5.7 kg is at rest on a perfectly smooth surface. A string pulls with a tension of 44.3N at an angle of 31 degress above the horizontal. How long will it take to reach a speed of 9.2 m/s?

 a) 0.91 s b) 1.04 s c) 1.2 s d) 1.38 s e) 1.59 s

4 A sled of mass 2.3 kg is on perfectly smooth surface. A string pulls with a tension of 18.3N. At what angle above the horizontal must the string pull in order to achieve an accelerations of 2.8 m/s2?

 a) 69.4 degrees b) 79.8 degrees c) 91.8 degrees d) 105.5 degrees e) 121.4 degrees