All categories

3 years ago

A car slows down from 80 km/h to 60 km/h in 2 seconds.

Physics

1 answer:

Andreyy893 years ago

6 0

Answer:

please mark brainlist

Explanation:

Initial speed u=80 km/h=80×185=22.22 m/s

Final speed v=60 km/h=60×185=16.67 m/s

Using v=u+at

Or 16.67=22.22+α×5

⟹ a=−1.1 m/s2

You might be interested in

ASAP pls answer right if can’t see picture don’t answer

Anna35 [415]

Answer:

Not sure but

F = m* a

32= 5 * a

a= 6.4 m/s^2

6 0

3 years ago

Cesium-137 undergoes beta decay and has a half-life of 30.0 years. How many beta particles are emitted by a 14.0-g sample of ces

Mandarinka [93]

Answer: $0.81\times 10^{16}$ beta particles

Explanation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass = 14.0 g

Molar mass = 137 g/mol

$\text{Number of moles of cesium}=\frac{14.0g}{137g/mol}=0.102moles$

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

1 mole of cesium contains atoms = $6.023\times 10^{23}$

0.102 moles of cesium contains atoms = $\frac{6.023\times 10^{23}}{1}\times 0.102=0.614\times 10^{23}$

The relation of atoms with time for radioactivbe decay is:

$N_t=N_0\times \frac{1}{2}^{\frac{t}{t_{\frac{1}{2}}}}$

Where $N_t$ =atoms left undecayed

$N_0$ = initial atoms

t = time taken for decay = 3 minutes

${t_{\frac{1}{2}}}$ = half life = 30.0 years = $1.577\times 10^7$ minutes

The fraction that decays : $1-(\frac{1}{2})^{\frac{3}{1.577\times 10^7}}=1.32\times 10^{-7}$

Amount of particles that decay is = $0.614\times 10^{23}\times 1.32\times 10^{-7}=0.81\times 10^{16}$

Thus $0.81\times 10^{16}$ beta particles are emitted by a 14.0-g sample of cesium-137 in three minutes.

7 0

3 years ago

What is the equation that relate electric potential (voltage) to electric field?

erma4kov [3.2K]

V= I x R
I= V / R
r= V / I

7 0

3 years ago

A battery supplies ________ to the circuit.

MariettaO [177]

Answer:

Electrical energy

Explanation:

Hope It helps you 

6 0

2 years ago

Read 2 more answers

A bag of sand has a density of 45 g/cm3 and a mass of 15 kg. How much space does the sand take up?

Aleks [24]

Volume = mass/density

Volume = 15000 g/45 g/cm3 ≈ 333.3 cm3

3 0

3 years ago

Read 2 more answers