Answer:
The speed at the bottom of the driveway is3.67m/s.
Explanation:
Height,h= 5sin20°= 1.71m
Potential energy PE=mgh= 2000×9.8×1.71
PE= 33516J
KE= PE- Fk ×d
0.5mv^2= 33516 - (4000×5)
0.5×2000v^2= 33516 - 20000
1000v^2= 13516
v^2= 13516/1000
v =sqrt 13.516
v =3.67m/s
 
        
             
        
        
        
Answer:
Motion of a racing car on a circular track
Explanation:
Uniform circular motion means the motion of the object is in a circle with a CONSTANT SPEED. 
The racing car will accelerate during its motion. Hence, it is not a uniform circular motion.
 
        
             
        
        
        
Answer:
 
    
Explanation:
To solve this problem we use the Hooke's Law:
 (1)
     (1)
F is the Force needed to expand or compress the spring by a distance Δx.
The spring stretches 0.2cm per Newton, in other words:
1N=k*0.2cm ⇒ k=1N/0.2cm=5N/cm  
The force applied is due to the weight

We replace in (1):
 
  
We solve the equation for m:
 
    
 
        
             
        
        
        
Answer:
Average speed = 0.35 m/s
Explanation:
Given the following data;
Distance = 1.3 Km
Time = 62 minutes
To find the average speed in m/s;
First of all, we would convert the quantities to their standard unit (S.I) of measurement;
Conversion:
1.3 kilometres to meters = 1.3 * 1000 = 1300 meters
For time;
1 minute = 60 seconds
62 minutes = X
Cross-multiplying, we have;
X = 62 * 60
X = 3720 seconds
Now, we can calculate the average speed in m/s using the formula;


Average speed = 0.35 m/s
 
        
             
        
        
        
<h2><u>We have</u>,</h2>
- Initial velocity (u) = 0 m/s
- Time taken (t) = 2.9s
- Acceleration due to gravity (g) = + 10 m/s² [Down]
<h2><u>To calculate</u>,</h2>
- Final velocity (v) 
- Height (h)
<h2><u>Solution</u><u>,</u></h2>
→ v = u + gt
→ v = 0 + 10(2.9)
→ v = 29 m/s  … ( Ans )
 … ( Ans )
And,
→ h = ut + ½gt²
→ h = 0(2.9) + ½ × 10 × (2.9)²
→ h = 5 × 8.41 
→ h = 42.05 m  … ( Ans )
 … ( Ans )