Answer:
3.69 m/s
Explanation:
Forces :
mgsin Θ - mumgcosΘ = ma
g x sinΘ - mu x g x cosΘ = a
9.8 x sin 21 - 0.53 x 9.8 x cos 21 = a
a = -1.337 m/s²
so you have final velocity = 0 m/s
initial velocity = ? m/s
Given d = 5.1 m
By kinematics
vf² = vo² + 2ad
0 = vo² + 2 x -1.337*5.1
vo = 3.69 m/s
Answer:
i) 0.7
ii) 1.39
iii) 0.6
Next time, when compiling a Physics question, ensure you put the unit of each measurement.
Explanation:
i) T = time of flight = 
where u = speed = 4, A = 60 and g = acceleration due to gravity = 10 (It is a constant);
Subsituting the values, we have: T =
= 0.7
ii) distance travel = Range = R = 
where u = speed = 4, A = 60 and g = acceleration due to gravity = 10 (It is a constant);
Subsituting values, we have: R =
= 1.39
iii) Maximum Height = H = 
where u = speed = 4, A = 60 and g = acceleration due to gravity = 10 (It is a constant);
Subsituting values, we have:
= 0.6
7kinetic energy is decreasing in B
Answer:
scratching a surface to make it rougher
increasing the size of a flying object
adding extra weight to an object
Explanation: