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Question
Repeat Exercise 5.18 with the contestant pulling the block of ice with a rope over his shoulder at the same angle above the horizontal as shown in Figure 5.21 (b).

#### Exercise 5.18

A contestant in a winter sporting event pushes a 45.0-kg block of ice across a frozen lake as shown in Figure 5.21(a). (a) Calculate the minimum force $F$ he must exert to get the block moving. (b) What is the magnitude of its acceleration once it starts to move, if that force is maintained?
Question Image Figure 5.21 A person sliding a block of ice on a frozen lake. (a) by pushing, (b) by pulling on a rope inclined above the horizontal.

a) $46.5 \textrm{ N}$

b) $0.656 \textrm{ m/s}^2$

Solution Video

# OpenStax College Physics Solution, Chapter 5, Problem 19 (Problems & Exercises) (6:48)

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3 votes with an average rating of 3.7.

## Calculator Screenshots Submitted by MEllis20 on Thu, 05/14/2020 - 01:06

This answer is incorrect. a) 51.04 and b) 0.719

Submitted by ShaunDychko on Sat, 05/16/2020 - 16:50

Hi MEllis20, thanks for the comment. I appreciate students keeping an eye out for mistakes. The answers you've given are for problem 18 where the person pushes at an angle below the horizontal, as in part (a) of the figure. In this problem (#19), the person pulls at an angle above the horizontal using a rope as in part (b) in the figure, and the force required is less than in problem 18, as expected since there is less normal force and thus less friction.
All the best,
Shaun