She ran for 3s
Put 18/6 because in order to find how long she ran for you need to divide the distance by the meters ran, once you do that you will get 3.
Answer:
The weight of measuring stick is 9.8 N
Explanation:
given information:
the mass of the rock,
= 1 kg
measuring stick, x =1 m
d = 0.25 m
to find the weight of measuring stick, we can use the following equation:
τ = Fd
τ = 0
-
= 0
F_{r} = the force of the rock
F_{s} = the force of measuring stick
![F_{s} =F_{r}](https://tex.z-dn.net/?f=F_%7Bs%7D%20%3DF_%7Br%7D)
= m g
= 1 kg x 9.8 m/s
= 9.8 N
thus, the weight of measuring stick is 9.8 N
The crate moves at constant velocity, this means that its acceleration is zero, so the net force acting on the crate is zero (Newton's second law).
There are only two forces acting on the crate: the force F applied by the worker and the frictional force, acting in the opposite direction:
![\mu m g](https://tex.z-dn.net/?f=%5Cmu%20m%20g)
, where
![\mu=0.25](https://tex.z-dn.net/?f=%5Cmu%3D0.25)
is the coefficient of friction and
![m=30.0 kg](https://tex.z-dn.net/?f=m%3D30.0%20kg)
is the mass of the crate. Since the net force should be equal to zero, the two forces must have same magnitude, so we have:
![F=\mu m g=(0.25)(30.0 kg)(9.81 m/s^2)=73.8 N](https://tex.z-dn.net/?f=F%3D%5Cmu%20m%20g%3D%280.25%29%2830.0%20kg%29%289.81%20m%2Fs%5E2%29%3D73.8%20N)
And so, this is the force that the worker must apply to the crate.
Answer:
44cm x 22cm
Explanation:
u= 10 cm
v= 1.1 cm
m=v/u= 1.1/10
m=11
hence the size of the image.
Answer:
3.97305 m
Explanation:
a = Acceleration due to gravity = 9.81 m/s²
If a jump lasts for 1.8 seconds this means that from the moment when the person leaves the ground till the person touches the ground again it takes 1.8 seconds. So, maximum height reached will be at half the time of the jump i.e., 0.9 seconds.
u = Initial velocity = 0
Equation of motion
![s=ut+\frac{1}{2}at^2\\\Rightarrow s=0t+\frac{1}{2}9.81\times 0.9^2\\\Rightarrow s=3.97305\ m](https://tex.z-dn.net/?f=s%3Dut%2B%5Cfrac%7B1%7D%7B2%7Dat%5E2%5C%5C%5CRightarrow%20s%3D0t%2B%5Cfrac%7B1%7D%7B2%7D9.81%5Ctimes%200.9%5E2%5C%5C%5CRightarrow%20s%3D3.97305%5C%20m)
So, height of the jump is 3.97305 m.