Look at the rock sitting on the hill in the picture above. Gravity should make the rock slide down the hill. What force is acting to balance gravity,keeping the rock in place? - D. friction
Centripetal force and momentum have to do with movement. Gravity cannot balance gravity.
Answer:
9.3 g/cm³
Explanation:
First, convert kg to g:
0.485 kg × (1000 g / kg) = 485 g
Density is mass divided by volume:
D = (485 g) / (52 cm³)
D = 9.33 g/cm³
Rounding to two significant figures, the density is 9.3 g/cm³.
Answer:
F = W + ma a> 0
Explanation:
For this exercise let's use Newton's second law
we assume the upward direction as positive
F - W = m a
F = W + ma
F = m (g + a)
In this case they indicate that the speed is less and less as it goes down, therefore the acceleration must be opposite to the speed, that is, the acceleration is upwards, consequently it is positive
We can see that since a> 0 the force F must have greater than the weight of the elevator
