Answer: Physical changes in nature could then be erosion in a mountain, the melting of snow, and a river freezing over from the cold. Since none of these changes affect the chemical composition of the mountain, the snow, or the river, they are physical changes.
Explanation:
Answer:
Ff = 19.6 N
Explanation:
So since its saying whats the minimum F to move the block, we will use static friction (0.5).
We will use the equation for force of friction, which is Ff = uFn
Ff = (0.5)(4)(9.8)
Ff = 19.6 N
this is the minumum force needed to move the block, as that is the frictional force. You would need to apply a minimum force of 19.6 N to move the block
Answer:
1)
Acceleration (a)=change in velocity/ change in time
Velocity (v)=90m/s
Time=0.0005s
a=90/0.0005
The acceleration =180000m/s^2 or 180km/s^2
Force = mass x acceleration
m=40g= 0.04kg
F= 0.04x 180000
F= 7200N or 7.2kN
Explanation: