Answer:
b. 0.20 m/s.
Explanation:
Given;
initial mass, m = 0.2 kg
maximum speed, v = 0.3 m/s
The total energy of the spring at the given maximum speed is calculated as;
K.E = ¹/₂mv²
K.E = 0.5 x 0.2 x 0.3²
K.E = 0.009 J
If the mass is changed to 0.4 kg
¹/₂mv² = K.E
mv² = 2K.E
Therefore, the maximum speed is 0.20 m/s
Answer:
1.3 m/s
Explanation:
(300N of Fa + 100N' of Fa) - 140N of Ff /200Kg
400N of Fa - 140N* of Ff
260 of ∑F/ 200kg = acceleration
a of piano = 1.3 m/s²
Remaining Distance = 180miles-90miles= 90miles
Time taken for first part of her journey= 90miles / 30miles/h= 3hours
To have average speed of 40mph,
Let the time taken for second part be xh
180 / 3h+xh =40
3+x= 4.5h
x =1.5h
Constant speed she must drive = 90miles / 1.5h = 60mph
