Answer:
12.495m/s
Explanation:
Horizontal displacement is the range of the projectile motion.
The range is expressed as;
R = 2U/g
U is the speed at which the rock is thrown (initial speed)
g is the acceleration due to gravity.
Given
R = 255cm = 2.55m
g = 9.8m/s²
Required
Speed U
Substitute the given parameters into the formula as shown;
2.55 = 2U/9.8
Cross multiply
2U = 2.55×9.8
2U = 24.99
U = 24.99/2
U = 12.495m/s
Hence the speed that you thew the rock is 12.495m/s
Great question !
The rate at which an object covers distance, without worrying
about the direction it's moving, is the object's SPEED .
When the direction is also given, then you have the object's VELOCITY.
This question is important. It gives us a chance to point out that
"velocity" is not just a fancy word for speed that you use when you
want to sound smart. There's actually an important difference between
'speed' and 'velocity'.
Answer:
The universal law of gravitation.
PE = m * G M / R^2 potential energy of mass m due to attractive forces
If the kinetic energy of mass m is greater than the energy due to the attractive masses then then mass m can continue indefinitely away from the attracting masses.
Answer: c) increases
Explanation:
Pressure increases with decreasing height
