Net force Quiz 1

Question 1

Your gym trainer suggests that you do some weightlifting in order to gain upper body strength and tone your muscles. Suppose that you begin your training with $$5 kg$$ weights that you lift vertically in such a way that you maintain a constant velocity of ascension as you lift them upwards. Determine the amount of force exerted by your muscles in lifting them this way.

Accepted Answer

$$49 N$$

Answer

$$19.6 N$$

Answer

$$56 N$$

Answer

$$9.8 N$$

Question 2

Teething is the process by which teeth erupt through the gums and is most often observed in puppies when they are around 4 months old. Suppose that you rescued two puppies of this age where they experience irritability and swollen gums which increases their tendency to chew on anything they can find to relieve teething pain. To redirect their urge to gnaw at household objects you get a chew toy over which both the puppies now begin to fight over. If one puppy pulls the $$800 g$$ toy with an acceleration of $$2 ms^{-2}$$ to the right and the other pulls it with an acceleration of $$3.5 ms^{-2}$$ to the left, determine the net force on the toy.

Accepted Answer

$$1.2 N$$ to the left

Answer

$$1.2 N$$ to the right

Answer

$$0.6 N$$ to the left

Answer

$$0.6 N$$ to the right

Question 3

Most warehouses and distribution centres utilize forklifts to lift and move cargo from one area to another. Suppose that a wooden crate of $$500 kg$$ was unloaded from a cargo truck onto the floor, and the forklift operator decides to push the crate without lifting it off the ground. How fast is the crate moving after sliding, under the force applied by the forklift in $$2 s$$? $$(	ext{Take the coefficients of static and kinetic friction to be} \mu_s = 0.30 	ext{and} \mu_k = 0.20 	ext{respectively})$$

Accepted Answer

$$1.96 ms^{-1}$$

Answer

$$0.98 ms^{-1}$$

Answer

$$0.49 ms^{-1}$$

Answer

$$2.45 ms^{-1}$$

Question 4

You decide to spend your winter break on a trip to Finland with your friends and go sledging under the Northern Lights as one of your friends suggests that visiting Lapland during Christmas calls for a mandatory reindeer-pulled sleigh ride. Suppose that the sledge of mass $$20 kg$$ is being pulled by Dasher, the fastest reindeer, as he accelerates at the rate of $$5 ms^{-2}$$.  If the coefficient of friction between the sledge and the snow is$$ 0.05$$, determine the net force acting on the sledge.

Accepted Answer

$$90.2 N$$

Answer

$$9.8 N$$

Answer

$$100 N$$

Answer

$$80.6 N$$

Question 5

Apple cultivation is often associated with the frigid climate of the Himalayan foothills, but the last decade saw a change in this outlook when horticulturists succeeded in growing apple trees commercially in the tropical climate of the Nilgiris. If a farmer harvests a lug full of apples that he needs to bring to the foothills from the top, determine the net force $$ F$$ acting on the $$10 kg$$ lug if it accelerates at the rate of $$1 ms^{-2}$$ upon being pushed and the coefficient of friction between the lug and the ground is $$ 0.75$$.<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/76b6b065-5e53-4051-8580-fb822a40edd03211063375447318021.png"/>

Accepted Answer

$$4.65 N$$

Answer

$$5.0 N$$

Answer

$$9.8 N$$

Answer

$$10.35 N$$