Answer:
Explanation:
Let the velocity of projectile be v and angle of throw be θ.
The projectile takes 5 s to touch the ground during which period it falls vertically by 100 m
considering its vertical displacement
h = - ut +1/2 g t²
100 = - vsinθ x 5 + .5 x 9.8 x 5²
5vsinθ = 222.5
vsinθ = 44.5
It covers 160 horizontally in 5 s
vcosθ x 5 = 160
v cosθ = 32
squaring and adding
v²sin²θ +v² cos²θ = 44.4² + 32²
v² = 1971.36 + 1024
v = 54.73 m /s
The radius, r, of the child from the center of the wheel is
r = 1.3 m
The wheel makes one revolution in 4.2 s. Its angular velocity is
ω = (2π rad)/(4.2 s) = 1.496 rad/s
The linear speed of the child is the tangential velocity, given by
v = rω
= (1.3 m)*(1.496 rad/s)
= 1.945 m/s
Answer: 1.95 m/s (nearest hundredth)
Answer: Heterogeneous mixture - the parts are not uniformly mixed.
A mixture contains components having distinct chemical properties. There are two types of mixtures: homogeneous and heterogeneous. In a homogeneous mixture there is uniform distribution of components. we cannot distinguish one portion of the mixture from another. for example salt mixed in water. In heterogeneous mixture, the components are not uniformly mixed. hence, we are able to distinguish different parts of a mixture, like the mixture of iron, sand and salt given in this question.
Answer:
D. The period would decrease by sqrt (2)
Explanation:
The period of a mass-spring system is given by:
where
m is the mass
k is the spring constant of the spring
If the spring constant is doubled,
k' = 2k
So the new period will be
So the correct answer is
D. The period would decrease by sqrt (2)
Answer:
2.89 hours
Explanation:
given :
Vo = 72 km/h
Vt = 90 km/h
S = 234 km
find : the time taken (t) = ?
solution :
2.a.s = Vt² - Vo²
2.a.(234) = 90²- 72²
468.a = 8100 - 5184
= 2916
a = 2916/468 = 6.23 km/h²
so,
t = (Vt-Vo) /a
= (90-72)/ 6.23
= 18/ 6.23
= 2.89 hours
